Hey,
I didn't have time to check the forums regularly. Apologies, if some ideas were suggested or are already planned for X2.
Either way, it's just details.
Soldiers should be able to "see" (notice) enemies within 1, maybe 2 tiles away when there's no obstruction between them. Happens when you were stepping through a door in X1 for example. Especially for the bigger aliens, this was a bit unrealistic.
Likewise, you should be able to hear when aliens close in on you. The visual clues, "sonar waves" you got in XCOM:EU could be an inspiration.
Both these points do not need to apply for all alien types. There may be sneaky ones and clumsy ones.
Moral could sink, the farther a soldier is away from other Xenonauts. Likewise moral could be more stable or increase in groups.
Moral loss should be higher when another Xenonaut dies right in front of you, near the affected soldier.
Interaction with ground forces/civilians
When a Xenonaut is close to civilians you should be able to give them simple commands. Take control over them for a moment with limited TUs or give them general commands like "go to(wards) dropship", "take cover". There may be a chance they don't listen, panic etc.
Especially ground forces should point you in the general direction where they, if they noticed alien activity.
I probably forgot some, so I might add more later.

Hello there!
I have to say, this thread made me pretty excited. Naturally, I wanted to share my thoughts, too.
As I'm only playing Xenonauts for a few weeks now, I might be wrong here and there due to not having seen it all.
I will probably switch over to the X2 discussion forum, but here are my general ideas.
First of all, the two questions:
Yes, I would definetely buy an improved/enhanced version of Xenonauts!
What I disliked about it: The Ground Combat got a bit repetitive after a while.
As a previous poster said, I too wouldn't mind aussaulting UFOs over and over again. The maps are a bit too monotonous or repeat themselves to often though. A random map generator or just a larger number of maps would help that of course. A few more settings like green, forest maps of different urban parts besides industrial like parks, market places, pedestrian zones, specific bigger structures like a theatre/opera with lots of parking space in front, power plants or gas stations.
Different kind of missions would certainly also do the trick.
The aliens might target infrastructure or military bases around the world, maybe nuclear manufacturing sites/storage!
Hence, you might have to defuse a bomb, stop an outright alien attack on a building of interest or might even have to target psi-controlled humans, like Mr. X and his crew/defending aliens have initiated a nuclear attack or just took control of nueclear operating systems yet and you have X amount of time to stop him.
Maybe even hostage situations caused by (non-controlled) crazies who got a hold on alien weaponry, thus justifying Xenonaut assistence.
Those kind of missions randomly appearing around the globe might also help a bit with the under-appreciation of australia in terms of radar coverage.
Full 3D: Just wanted to point out, that I have the same worries as most of the posters here. Huge fan of the Baldur's Gate series!
A 90 degree rotatable camera (4 angles) for ground combat would be fine, but please try to keep the look of the "control room". I really like the style of the main menu, loading save games, soldier looks etc.
Additionally to the rotatable camera, the possibility to get a first person view of a soldiers line of sight would be cool!
XCOM Cover System: While easy to learn, the system was also very dull and flawed in a few aspects. On harder difficulties it was basically: take full cover (and spam overwatch) or die. An indication, how much of an cover you get would be helpful though.
Soldier Colour Customisation: Yes!
Also, placing your soldiers in order from 1 to 8 - if not already possible? - would be very convenient. Maybe the possibility of assigning squads, not only a place in your dropship. A few more countries, names, faces and a KIA list/memorial.
More importantly I would like to emphasise the emotional attachment to your soldiers. The badges should be kept, maybe even appear on the soldiers uniform?
Some soldiers might have "random" (maybe tied to minimum stats) quirks. For example, being able to throw grenades farther (base strength 55+) or better eyesight.
I'd like to be able to hire pilots, too.
This would make the loss of an interceptor much worse. There should be a chance for the pilot to survive though, via ejector seats.
Stats might include reaction/reflexes for dodging, accuracy and like infantry, stamina to counter combat fatigue. You have to rotate your soldiers more often.
Enough rambling here for now.
Keep up the good work, Chris and colleagues!